Biomedical materials surface properties

A new material with good antithrombogenic properties, suitable as biomedical material which assures the endothelialization of the inner surface of a polyurethane tube to imitate the inner wall of a natural blood vessel has been synthesized by blending PVA with polycarbonate urethane)(PCU) [229],... 

Polyurethanes were first suggested for use as biomaterials in 1967 [36]. Polyurethane materials have excellent mechanical properties, making them suitable for many different biomedical applications. Currently, a variety of polyurethanes are used in biomedical devices like coatings for catheters and pacemaker leads (Table A.2). The biocompatibility of biomedical polyurethanes appears to be determined by their purity i.e., the effectiveness of the removal from the polymer of catalyst residues and low molecular weight oligomers [37]. The surface properties of commercially available polyurethanes, which are critically important in determining biocompatibility, can vary considerably, even among lots of the same commercially available preparation [38]. 

Lin, H., et al., Synthesis, surface, and cell-adhesion properties of polyurethanes containing covalently grafted RGD-peptides. Journal of Biomedical Materials Research, 1994, 28, 329-342. 

Protein adsorption at an interface is of importance for many reasons. Foremost amongst these is that the surface properties of the substrate material are inevitably altered as a result of contact with a protein-containing solution. The substrate may be either a solid or liquid. There are many areas in which such phenomena have direct technological applications including emulsion stabilization, hydrophobic chromatography, biomedical devices, enzyme immobilization and immunology. 

The success of a tissue engineering scaffold or a drug carrier depends mainly on its surface properties. The surface of a polymeric biomaterial is defined with respect to the biomedical application and the host tissue environment in which the material is intended to perform. Biocompatibility of a polymer implant is directly related to its surface properties. A polymer implant with rough surface accelerates thrombus... 

Buyle, G., Heyse, R, Ferreira, 1., 2010. Tuning the surface properties of textile materials. In Rausher, H., Perucca, M., Buyle, G. (Eds.), Plasma Technology for Hyperfunctional Surfaces—Food, Biomedical Textile Application. Wiley-VHC, Weinheim, pp. 135-182. 

Kim, H. Y. Yasuda, H. K. (1999) Improvement of fatigue properties of poly(methyl methacrylate) bone cement by means of plasma surface treatment of fillers. Journal of Biomedical Materials Research, 48, 135-142. 

Microchannels that range in diameter from tens to hundreds of microns have emerged as potentially powerful tools for a variety of biomedical applications. They can be used to minimize sample volume and reduce costs, as well as to increase throughput and analysis sensitivity. Since microfluidic devices operate at small length scales, their functionality is greatly dependent on their surface properties, which vary depending on the type of material that is used to fabricate the channel and the subsequent surface modifications. 

Recently, a new approach using enzymes to modify material (or nanomaterial) surfaces has been developed. This approach utilizes enzymatic hydrolysis or degradation to mildly etch the material surfaces and thus CTeate desirable surface structures or properties [45]. Many polymers, including polyvinyl chloride (PVC), polyaayloni-trile, polyethylene terephthalate, and polyamides, have been modified by this method. In a recent study, PVC tubes were soaked in Rhizopus arrhizus lipase to create nanometer surface features that exhibited antibacterial properties [60]. Enzymatic modification demonstrates great potential and promise for biomedical and nanomedicine applications due to its biocompatible, environmentally friendly, and simple process. 

There is currently a renewed interest in the use of electrospinning techniques for the fabrication of membranes. Chapter 8 reviews the use of this versatile technique for the production of nanofiber webs or membranes. The chemical and physical properties of nanofiber manbrane surfaces play an important role in their application to filtration, biomedical materials, tissue engineering scaffolds, drug delivery... 

Kennan, J. J., Peters, Y. A., Swarthout, D. E., Owen, M. J., Namkanisom, A. Chaudhury, M. K. (1997) Effect of saline exposure on the surface and bulk properties of medical grade silicone elastomers. Journal of Biomedical Materials Research, 36, 487—497. 

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